| /* getifaddrs -- get names and addresses of all network interfaces |
| Copyright (C) 2002, 2003 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <ifaddrs.h> |
| #include <net/if.h> |
| #include <sys/socket.h> |
| #include <sys/ioctl.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <netinet/in.h> |
| |
| #include "ifreq.h" |
| |
| /* Create a linked list of `struct ifaddrs' structures, one for each |
| network interface on the host machine. If successful, store the |
| list in *IFAP and return 0. On errors, return -1 and set `errno'. */ |
| int |
| getifaddrs (struct ifaddrs **ifap) |
| { |
| /* This implementation handles only IPv4 interfaces. |
| The various ioctls below will only work on an AF_INET socket. |
| Some different mechanism entirely must be used for IPv6. */ |
| int fd = __socket (AF_INET, SOCK_DGRAM, 0); |
| struct ifreq *ifreqs; |
| int nifs; |
| |
| if (fd < 0) |
| return -1; |
| |
| __ifreq (&ifreqs, &nifs, fd); |
| if (ifreqs == NULL) /* XXX doesn't distinguish error vs none */ |
| { |
| __close (fd); |
| return -1; |
| } |
| |
| /* Now we have the list of interfaces and each one's address. |
| Put it into the expected format and fill in the remaining details. */ |
| if (nifs == 0) |
| *ifap = NULL; |
| else |
| { |
| struct |
| { |
| struct ifaddrs ia; |
| struct sockaddr addr, netmask, broadaddr; |
| char name[IF_NAMESIZE]; |
| } *storage; |
| struct ifreq *ifr; |
| int i; |
| |
| storage = malloc (nifs * sizeof storage[0]); |
| if (storage == NULL) |
| { |
| __close (fd); |
| __if_freereq (ifreqs, nifs); |
| return -1; |
| } |
| |
| i = 0; |
| ifr = ifreqs; |
| do |
| { |
| /* Fill in pointers to the storage we've already allocated. */ |
| storage[i].ia.ifa_next = &storage[i + 1].ia; |
| storage[i].ia.ifa_addr = &storage[i].addr; |
| |
| /* Now copy the information we already have from SIOCGIFCONF. */ |
| storage[i].ia.ifa_name = strncpy (storage[i].name, ifr->ifr_name, |
| sizeof storage[i].name); |
| storage[i].addr = ifr->ifr_addr; |
| |
| /* The SIOCGIFCONF call filled in only the name and address. |
| Now we must also ask for the other information we need. */ |
| |
| if (__ioctl (fd, SIOCGIFFLAGS, ifr) < 0) |
| break; |
| storage[i].ia.ifa_flags = ifr->ifr_flags; |
| |
| ifr->ifr_addr = storage[i].addr; |
| |
| if (__ioctl (fd, SIOCGIFNETMASK, ifr) < 0) |
| storage[i].ia.ifa_netmask = NULL; |
| else |
| { |
| storage[i].ia.ifa_netmask = &storage[i].netmask; |
| storage[i].netmask = ifr->ifr_netmask; |
| } |
| |
| if (ifr->ifr_flags & IFF_BROADCAST) |
| { |
| ifr->ifr_addr = storage[i].addr; |
| if (__ioctl (fd, SIOCGIFBRDADDR, ifr) < 0) |
| storage[i].ia.ifa_broadaddr = NULL; |
| { |
| storage[i].ia.ifa_broadaddr = &storage[i].broadaddr; |
| storage[i].broadaddr = ifr->ifr_broadaddr; |
| } |
| } |
| else if (ifr->ifr_flags & IFF_POINTOPOINT) |
| { |
| ifr->ifr_addr = storage[i].addr; |
| if (__ioctl (fd, SIOCGIFDSTADDR, ifr) < 0) |
| storage[i].ia.ifa_broadaddr = NULL; |
| else |
| { |
| storage[i].ia.ifa_broadaddr = &storage[i].broadaddr; |
| storage[i].broadaddr = ifr->ifr_dstaddr; |
| } |
| } |
| else |
| storage[i].ia.ifa_broadaddr = NULL; |
| |
| storage[i].ia.ifa_data = NULL; /* Nothing here for now. */ |
| |
| ifr = __if_nextreq (ifr); |
| } while (++i < nifs); |
| if (i < nifs) /* Broke out early on error. */ |
| { |
| __close (fd); |
| free (storage); |
| __if_freereq (ifreqs, nifs); |
| return -1; |
| } |
| |
| storage[i - 1].ia.ifa_next = NULL; |
| |
| *ifap = &storage[0].ia; |
| |
| __close (fd); |
| __if_freereq (ifreqs, nifs); |
| } |
| |
| return 0; |
| } |
| #ifndef getifaddrs |
| libc_hidden_def (getifaddrs) |
| #endif |
| |
| void |
| freeifaddrs (struct ifaddrs *ifa) |
| { |
| free (ifa); |
| } |
| libc_hidden_def (freeifaddrs) |